Hi Green and welcome to the site! Once you have obtained sufficient reputation, you will no longer require approval on your posts.
This is to prevent unwanted spam. In SE there are many moderators who can quickly detect and delete spam however this isn't yet the case on our site. Hopefully as we progress and become more popular, we can one day allow new users to post without approval.
With regards to images, there is a tutorial on meta on how best to obtain the image link.
Make sure to see Sammy Gerbil's comment on the answer above.